Chick has squishy ball on chest

[Dfwchickenchick]

Hello my chick has a squishy ball on his/her chest. We let the hens hatch 3 chicks this summer and they are doing well. They were born in early July. The hens never let us get close to the chicks but they have all been exploring and walking around and acting normal so we haven’t been concerned. Today one of my hens was not leaving the coop and she had one of the chicks in there with her and when I took her out she went right back in. I thought she was sick or egg bound but she laid an egg while I watched so I know it wasn’t that. But she isn’t letting the chick out of her sight or the coop. What could this be? the chick doesn’t smell, and is eating and drinking.

 

[Eggcessive]

Is that the chick’s crop or does it feel like air under the skin? Can you examine the other chick’s crop in their upper right chest?